<template>
  <div class="todo-footer" v-if="total">
    <label>
      <input type="checkbox" :checked="isAll" @change="checkAll"/>
    </label>
    <span>
      <span>已完成{{doneTotal}}</span> / 全部{{total}}
    </span>
    <button class="btn btn-danger" @click="clearHasDone">清除已完成任务</button>
  </div>
</template>

<script>
	export default {
		name: "MyFooter",
		props: ['todos', 'checkAllTodo', 'clearAllDoneTodos'],
		computed: {
			total() {
				return this.todos.length;
			},

			doneTotal() {
				// let count = 0;
				// this.todos.forEach(item => {
				// 	if (item.done) {
				// 		count++;
				// 	}
				// });
				// return count;
				return this.todos.reduce((pre, cur) => {
					return pre + (cur.done ? 1 : 0);
				}, 0);
			},
			isAll() {
				return this.doneTotal === this.total && this.total > 0;
			}
		},
    methods: {
			checkAll(e) {
        this.checkAllTodo(e.target.checked);
			},
			clearHasDone() {
				console.log("清除已完成");
				this.clearAllDoneTodos();
      }
    }
	}
</script>

<style scoped>
  /*footer*/
  .todo-footer {
    height: 40px;
    line-height: 40px;
    padding-left: 6px;
    margin-top: 5px;
  }

  .todo-footer label {
    display: inline-block;
    margin-right: 20px;
    cursor: pointer;
  }

  .todo-footer label input {
    position: relative;
    top: -1px;
    vertical-align: middle;
    margin-right: 5px;
  }

  .todo-footer button {
    float: right;
    margin-top: 5px;
  }

</style>
